Paper 3 Physics

Question 1

If given 10 oscillations and need to calculate percentage uncertainty of 1 oscillation how do you do it?

Answer 1

Calculate the percentage uncertainty in 10 oscillation time. This is your percentage uncertainty in you value of time for one oscillation.

0.1/ time value for 10 oscillations x100

Percentage uncertainty if unaffected by multiplying or dividing by constants. The percentage uncertainty Is always taken from the value you ACTUALLY measured or read or took.

Question 2

Why is It important to use a voltmeter with very high resistance when taking a potential difference reading across a capacitor?

Answer 2

To ensure the capacitor does not lose charge through the meter. This would affect the p.d. value taken.

Question 3

If a question asks you to calculate 2% of a specific value how many significant figures should you give the answer to?

Answer 3

As many as the percentage uncertainty. If 2%, then 1s.f.